Oswalt's Back, Breaking Stuff and Whiffs

Roy Oswalt has garnered plenty of interest in free agency since word came out that he's seeking a one-year deal. The 34-year-old isn't considering all teams (sorry, Toronto and Cleveland), seemingly having his sights set on Texas, St. Louis or possibly Boston. Depending upon the condition of his troublesome lower back, Oswalt could be could be on the backside of a superb career or primed for a huge comeback season in 2012.

Overall, Oswalt's 2011 campaign was arguably the worst of his career. He was limited to 139 innings, striking out a career-low 15.7% of batters faced and posting a 105 ERA+. It was the first time that the former 23rd-round pick failed to crack two Wins Above Replacement since his 2001 debut. But Oswalt's season can be broken down into two drastically different parts: when his back injury may have limited his pitch selection, and when he returned to health (at least for the time being) late in the year.

Oswalt's back caused him to hit the DL twice in 2011, as he missed nearly three weeks from late April to mid-May and then nearly five weeks from late June to early August. Keep that in mind as you look at Oswalt's miss percentage by month:

Month	Miss Pct.
April	19.2
May	11.2
June	15.8
August	20.8
September	22.6
Avg. for SP	19.8

Oswalt wasn't fooling anyone when his back bothered him, but he started to look like his old self as the season came to a close. The major change for Oswalt in August and September was that he started throwing his breaking stuff more often. Perhaps as a result of his bad back, Oswalt preferred to go to his changeup more in place of his curveball and slider during the first three months of the year:

Month	Changeup Pct.	Curveball/Slider Pct.
April	22.3	14.8
May	25.9	15.8
June	16.1	16.6

Considering that his changeup gets swings and misses half as often (13 percent) as his breaking stuff (26 percent), that was a bad trade-off.

The curve and slider made a comeback later in the year, though. He broke out the breaking stuff far more often after returning from his second DL stint in August:

Month	Changeup Pct.	Curveball/Slider Pct.
August	14.3	27
September	18.5	23.7

If Oswalt has his full arsenal and can hold up for 150 or so innings in 2012, he should be a great get for the Cardinals, Rangers or Red Sox. If his back limits him to being more of a fastball/changeup pitcher, however, don't expect a big rebound in Ks.